Internal turbo wastegate movement / clearance

[wilbo666]

I've got some dump flanges for turbos (massive kudos to MrDOHC ! ). The flanges are designed (by me) to split the wastegate and main flow.

I'm curious as to the range of movement the wastegate flap encounters in operation!

Depending on how much movement the wastegate flap needs my design may cause the wastegate flap to hit my flange...

It isn't a drama for me to modify the flange / wastegate outlet; and I suspect that going on the side of caution is what I should do, but I am still interested the answer!

Pics to show what I mean!







Cheers
Wilbo

[Talasas]

It's doubtful that is will move that far, the stock wastegate on my CT9 only opens about 45 degrees at most, probably less. I did the same with my downpipe flange, and then put the wastegate actuator on and it didn't even come close.

That being said you should test it with your actuator if you can, but I still doubt it will open quite so far.

[wilbo666]

The thing is the exahust gases will push on the flap with a large amount of force which I can't really simulate out of the car.

Simply applying pressure to the actuator won't really show what the movement will be in use (no exhaust gas pressure)...

I did look at the actuator, and try and determine what the maximum extended length could be. Not knowing the internal design tho it looks like there might be enough movement to extend past the angle where the flange would block it...

Cheers
Wilbo

[30psi 4agte]

I tend to agree with Talasas. There isnt much movement in them. The wastegate actuator rarely opens fully ( totaly extended) on any setup.

Example : My old turbo would only push the gate open approx 45deg at over 9000 rpm.

If you run a slightly larger pipe than the wastegate flap it should have plenty ov clearence for the flap to open all the way if needed any way

[Talasas]

The thing is the exahust gases will push on the flap with a large amount of force which I can't really simulate out of the car.

The point you're missing is once it's attached to the actuator it can only move as far as the actuator allows it. You can simulate this by hooking up the actuator arm and pulling it out as far as it goes by hand. I figure won't open more than that.

[Sam_Q]

a bit of a side topic but have thought about making and installing a divider so that the exhuast wheel gases don't go near the wastegate?

[wilbo666]

The point you're missing is once it's attached to the actuator it can only move as far as the actuator allows it. You can simulate this by hooking up the actuator arm and pulling it out as far as it goes by hand. I figure won't open more than that.

OK, I wasn't sure if pulling on the actuator fully would damage it, but now I think about it can't see that it would

Ta!

I'll give that a go and see what the outcome is!

a bit of a side topic but have thought about making and installing a divider so that the exhuast wheel gases don't go near the wastegate?

Yep I'm already planning to do that

Cheers
Wilbo

[RobertoX]

then you can have the wastegate pipe just venting straight down.. screamer for extra noise

[Sam_Q]

then you can have the wastegate pipe just venting straight down.. screamer for extra noise

thats not quite what I had in mind but yeah you could do that

apparently not having the wastegate air and exhuast air join for atleast 30cm is the optimum

[wilbo666]

Pic is fully extended (looks about 45deg ish)

You guys were well right



If I was making them again I would have moved the wastegate circle closer to the top to allow a smoother flow for the wastegate gases...live and learn I guess

Cheers
Wilbo

[30psi 4agte]

Cant you just grind it out with a die grinder ?

[wilbo666]

Cant you just grind it out with a die grinder ?

Yes I could, but if I had of placed the hole further to the top when I designed then I wouldn't need to

Also if I grind it out to an oval as opposed to a circle it will make the connecting of the wastegate pipe slightly more difficult.

Cheers
Wilbo

[brett_celicacoupe]

oval the inside edge then.

leave the pipe side of the plate round

[thechuckster]

jeez - wilbo's small dremel will die carving out that plate? Or is that steel reasonably easy to grind?

And do we get to call Phil Doctor Flange when we see him next?

[wilbo666]

jeez - wilbo's small dremel will die carving out that plate? Or is that steel reasonably easy to grind?

dremel would die...

But new favourite tool = power file

And do we get to call Phil Doctor Flange when we see him next?

Indeed!

Cheers
Wilbo

[roadsailing]

i'd grind out the hole into a "D" shape, let it open all the way.

leaving it liek that might not cause any issues, but why take the risk? it will be a bitch to get back in there and fix it.

[wilbo666]

i'd grind out the hole into a "D" shape, let it open all the way.

leaving it liek that might not cause any issues, but why take the risk? it will be a bitch to get back in there and fix it.

It is open as far as it can open in that picture But the flow from the wastgate is somewhat obscured by the flange...

Geez guys

All I was saying was that if I was making them again then I'd be moving the circle close to the top! And if that was the case hooking up the pipe for the wastegate would be easier.

Hindsight is 20-20 and all that

I'll enlarge it and deal with the extra PITA of the wastgate pipes, but meh it still would have been easier if I designed it better to start with

Cheers
Wilbo

[devolutio]

Pic is fully extended (looks about 45deg ish)

You guys were well right

Even though that is as far as the wastegate opens, it doesn't look like it provies much of an escape route for the bypassing gasses, normally they would be able to get out sideways and meet up with flow from the turbine. If that is as far as it opens, then theres a chance it will overboost right when you don't want it to (ie: huge revs, wastegate open all the way, easier for exhaust to flow through the turbine rather than the restrictive wastegate).

I'm not an expert, just putting forward an idea (hell i've never even driven a turbo car!) but I'd get it looked at by someone in the know, and possble make the area around the wastegate quite a bit bigger (or get a file and taper the edge that bolts to the turbo).

If I was making them again I would have moved the wastegate circle closer to the top to allow a smoother flow for the wastegate gases...live and learn I guess

ok just read that, wastegate flap getting stuck open due to poor design - no biggie... no boost engine lives. overboosting at high rpm due to restrictive wastegate - yeah work that one out before you test it.

cheers

[wilbo666]

I'll enlarge it and deal with the extra PITA of the wastgate pipes, but meh it still would have been easier if I designed it better to start with

Cheers
Wilbo

Cheers
Wilbo

[devolutio]

ahh, we both posted at 9:13am (I finally got jibbed by daylight savings and was supposed to start work at 9:30 - oops)